Introduction. Turner's syndrome is due to the absence or anomaly of an X chromosome, resulting in short stature, gonadal dysgenesis and various physical characteristics. The association of this syndrome with other alterations such as autoimmune diseases has been described and, in rare cases, coexists with Klippel-Feil syndrome. We undertook this study to report the case of a female with Turner's syndrome with mosaicism (45,X/46,XX/ 47,XXX) with the coexistence of Klippel-Feil syndrome. Case report. We present the case of a female patient with short stature and physical characteristics of Turner's syndrome. The patient presented with limitations of neck movement with a forced position to the right side of her skull. Karyotype showed a chromosomal complement (45,X/46,XX/47,XXX). Radiologically, fusion of the first and fifth cervical vertebrae and vertebral fusion of the seventh cervical vertebra with the first thoracic vertebra were observed. Conclusion. This may represent the first case of Turner's syndrome associated with a cytogenetic variety of Klippel-Feil syndrome.